ARM: ixp4xx: Delete old PCI driver

ARM: ixp4xx: Delete old PCI driver

We are just using the new PCI driver in the proper PCI host
drivers folder: drivers/pci/controller/pci-ixp4xx.c.

The new driver does not support indirect PCI but it has
turned out noone is using this. If the feature is desired
we have ways to implement it, suggested by John Linville.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220211223238.648934-4-linus.walleij@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>